Research On Power Distribution For Regenerative Braking System Of Electric Vehicles

Under the general trend of energy conservation and environmental protection,the electric vehicle industry has made great progress,but the short driving range is one of the key issues that restrict the industrialization of electric vehicles.In order to extend the service life of the battery and increase the driving range of the electric vehicle,the regenerative braking technology and the composite power supply technology have been extensively studied.Regenerative braking system can recover part of the energy during braking and increase the utilization of energy.The composite power system composed of battery and supercapacitor has their own advantages,which can reduce the damage of large current to the battery and prolong the service life of the battery.At the same time,the power and driving range of the car are improved due to the addition of supercapacitor.This paper taked pure electric vehicles as the research object and conducted research on two aspects of regenerative braking and composite power system.The main research contents included:1)Analyzed the influencing factors of regenerative braking of torque distribution and the torque distribution relationship of braking process and the regenerative braking energy recovery process.Considered the vehicle speed,braking strength,battery and supercapacitor's SOC,a regenerative braking based on fuzzy control was proposed.It can recover energy to the utmost.2)Analyzed the topology of the composite power system,selected the topology of the supercapacitor through the DC/DC converter and the battery in parallel on the power bus,and improved the structure;analyzed the working characteristics and working mode of the composite power system.Considered several factors,the composite power supply control strategy of this paper was designed.3)Established a composite power supply model and a regenerative braking control strategy model in the MATLAB/Simulink environment.The composite power model includeed a battery model,a supercapacitor model,a DC/DC model,and a power distribution control strategy model.The regenerative braking control strategy model includeed a front and rear wheel braking force distribution model and a regenerative braking fuzzy controller model.4)On the vehicle simulation platform ADVISOR,developed the electric vehicle model with composite power module,and simulated the regenerative braking control strategy and composite power distribution strategy under UDDS and NYCC conditions.The results showed that the control strategy of this paper effectively improved the recovery efficiency of regenerative braking and the recovery efficiency of vehicle braking energy.